VGX Texture/surface mapping

[Marc Andreessen]

I don't have access to a VGX at the moment, but I'm very curious as
to how the hardware texture/surface/image-mapping works.  I understand
it's done with the extra bitplanes; how does that work?  Can it be fed
arbitrary images?  I saw an SGI demo videotape way back when, with a
VW Bug 'reflecting' its environment (which wasn't actually being rendered);
the SGI rep called this (I think) environment mapping.  How does that
work?

As if that weren't enough:  What additions have been made to the pipeline
and GL to handle all this?  What's the performance penalty?  And finally,
given that this (as well as, I understand, atmospheric effects) is now
supported in hardware, what's left to be implemented within the GL paradigm?

Marc

-- 
Marc Andreessen___________University of Illinois Materials Research Laboratory
Internet: andreessen at uimrl7.mrl.uiuc.edu____________Bitnet: andreessen at uiucmrl